﻿#region LicenseHeader

// Copyright 2012 The Trustees of Indiana University.  All rights reserved.
// 
// The Indiana University licenses this file to you under the Apache License, 
// Version 2.0 (the "License"); you may not use this file except in compliance 
// with the License.  You may obtain a copy of the License at 
// 
// http://www.apache.org/licenses/LICENSE-2.0
// 
// Unless required by applicable law or agreed to in writing, software 
// distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
//  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  
// See the License for the specific language governing permissions and 
// limitations under the License.
// 
// @author Thilina Gunarathne (tgunarat@indiana.edu)

#endregion

#region

using System.Collections.Generic;
using AzureMRCore.DataTypes;
using AzureMRCore.Partitioners;

#endregion

namespace AzureMRCore.OutputCollectors
{
    public class MapOutputCollector<K, V> : IOutputCollector<K, V>
        where K : Key
        where V : new()
    {
        private readonly Dictionary<int, List<KeyValuePair<K, V>>> _outputs;
        private readonly IPartitioner _partitioner;

        public MapOutputCollector(IPartitioner partitioner)
        {
            _partitioner = partitioner;
            _outputs = new Dictionary<int, List<KeyValuePair<K, V>>>();
        }

        #region IOutputCollector<K,V> Members

        public void Collect(K key, V value)
        {
            var pair = new KeyValuePair<K, V>(key, value);
            int reducerID = _partitioner.GetReducerID(key);
            if (_outputs.ContainsKey(reducerID))
            {
                List<KeyValuePair<K, V>> values = _outputs[reducerID];
                values.Add(pair);
            }
            else
            {
                var values = new List<KeyValuePair<K, V>>();
                _outputs.Add(reducerID, values);
                values.Add(pair);
            }
        }

        #endregion

        public Dictionary<int, List<KeyValuePair<K, V>>> GetResults()
        {
            return _outputs;
        }
    }
}